The invention relates generally to mold inhibitors and, more specifically to a mold inhibitor containing propionic acid to which an essential oil has been added to reduce its corrosiveness and improve its efficacy.
Grains and grain products can develop molds that produce mycotoxin compounds either prior to harvest or while in storage. High moisture content in the grains or grain products, particularly including animal feeds, promotes the development of mold and mycotoxin production. Mold inhibitors can be added to feeds to inhibit this development. Of all the mold inhibitors currently available at an economical price, propionic acid is the most efficacious. This acid is Generally Recognized as Safe (GRAS) by FDA, available in liquid or dry formulations, of low toxicity to animals, and economical for addition to feeds at an effective level. While the use of propionic acid-based mold inhibitors has become widespread in many countries, it is well recognized that feed mill managers are very sensitive to corrosive problems associated with the usage of mold inhibitors that are sprayed on to their feeds for non-nutritional purposes. There is a need, accordingly, for a less corrosive efficacious mold inhibitor.
The main types of mold inhibitors are based on organic acids. The most effective liquid mold inhibitors are based on propionic acid (Dixon, R. C. and Hamilton, P. B., (1981), Effect of Feed Ingredients on the Antifungal Activity of Propionic Acid, Poultry Science, 60, 2407–2411; Sofos, J. N., (1994) “Antimicrobial Agents in “Food Additive Toxicology”, Eds, Joseph A. Maga and Anthony T. Tu., Marcel Dekker, Inc. New York, USA). These formulations are made using either free propionic acid or salts of propionic acid. In addition, there are mold inhibitor formulations existing with propionic acid in combination with other ingredients, including the formulations in U.S. Pat. Nos. 4,770,878; 4,806,353; 4,847,067; 4,963,366; and 6,183,794 B1.
Recently it has been proved that essential oils showed marked activity against some Gram-positive and Gram-negative bacteria and yeast (Hili, P, Evans, C. S., and Veness, R. G., (1997), Antimicrobial Action of Essential Oils: The Effect of Dimethylsulphoxide on the Activity of Cinnamon Oil, Letters in Applied Microbilogy, 24, pp 269–275). The antimicrobial activity was greater if the essential oil contained geraniol (Cruz, u., Cabo, M. M., Castillo, M. J., Jimenez, J., Ruiz, C., and Ramos-Cormenzana, A., (1993), Chemical Composition and Antimicrobial Activity of Essential Oils of Different Samples of Thymus Bacticus Boiss, Phytotherapy Research, 7, pp 92–94). Essential oils are the odorous, volatile products of plants. The function of essential oils is believed to be largely communicative and a variety of complex interactions have evolved enabling plants to utilize essential oils to influence their environment.